The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
FIG. 1 is a schematic diagram illustrating the networking of a single network of Next Generation Network (NGN). As shown in FIG. 1, the Media Gateway Controller (MGC) and Media Gateway (MG) are two key components of NGN. The MGC is in charge of the call control function while the MG is in charge of the service bearer function, which separates the call control plane from the service bearer plane, so as to share network resources sufficiently and simplify the device upgrading and the service extension, thereby lower the development and maintenance cost greatly.
In order to make an MG cooperate with an MGC, a media gateway control protocol is needed between the MGC and the MG. The media gateway control protocol is a major protocol used in communication between an MG and an MGC, and two of such protocols widely used are H.248/MeGaCo and MGCP.
MGs usually establish a Real-time Transmission Protocol (RTP) media streams between each other to communicate under the control of an MGC.
According to different network positions where MGs are located, an MG may have two functions. The first function is to bear media streams in a single IP domain as User Network Interface (UNI), for example, the interconnecting in a same IP domain of a single operator, such an MG is also called a common MG; the second function is to bear cross-domain media streams in multiple IP domains as Network Node Interface (NNI), for example, the interconnecting among the IP domains of different operators or among the different IP domains of a same operator, typically, between an enterprise network and a core network, such an MG is also called a BG or an IP-IP MG. So far, a BG has been suggested to be needed in the implementation of interconnecting between different IP domains but no specific implementing method is given.
At present, there are various IP domains in which constitution mechanisms of the media streams may be different, such as different IP subnet addresses of an IP network, interconnecting IPv4 and IPv6 networks, and different media coding/decoding algorithms. Along with the development of services, it has become a pressing need to make these media streams of different IP networks interconnect.